Suction attachment with a corner having a secondary suction opening

ABSTRACT

The invention relates to a suction attachment ( 9 ) for a vacuum cleaner. The suction attachment comprises a housing ( 11 ) having two edges ( 43, 45 ) enclosing an angle α in a corner portion. A primary suction opening ( 55, 59 ) extends in a bottom part ( 57 ) of the suction attachment along each of the two edges, said primary suction openings being connected to a connecting channel ( 21 ) which can be coupled to a suction unit ( 7 ) of the vacuum cleaner. The primary suction openings open into a secondary suction opening ( 61 ) near said corner portion.  
     According to the invention, the suction attachment ( 9 ) comprises at least two suction portions ( 35, 37 ), wherein said two edges ( 43, 45 ), said two primary suction openings ( 55, 59 ) and said secondary suction opening ( 61 ) are provided in a first one of the suction portions ( 35 ), and at least a second one of the suction portions ( 37 ) is provided with a suction opening ( 67, 69, 71 ) which can be shut off from the connecting channel ( 21 ). By shutting off the suction opening of said second suction portion from the connecting channel, the suction power of suction unit ( 7 ) is concentrated, partially or completely, in the suction openings of the first suction portion. As a result, a comparatively high suction power is also obtained in the corner portion of the first suction portion where the secondary suction opening ( 71 ) is situated. Said corner portion thus enables a comparatively high cleaning performance to be achieved in narrow areas or corners of a surface ( 5 ) to be cleaned.  
     In a preferred embodiment, the suction attachment ( 9 ) comprises two suction portions ( 35, 37 ) which jointly form a foot ( 39 ), which foot is rotatable about a center portion ( 31 ) of the suction attachment. Both suction portions comprise a corner portion having a secondary suction opening ( 61, 71 ) for cleaning narrow areas or corners of a surface ( 5 ) to be cleaned. The suction power of the suction unit ( 7 ) can be concentrated in each of the two suction portions by rotating the foot from a first position through +90° and −90°, respectively, about the center portion.

[0001] The invention relates to a suction attachment for a vacuum cleaner, which suction attachment comprises a housing having two edges enclosing a corner, a primary suction opening extending in a bottom part of the suction attachment along each of the two edges, said primary suction openings being connected to a connecting channel which can be coupled to a suction unit of the vacuum cleaner, and said primary suction openings opening into a secondary suction opening near said corner.

[0002] The invention also relates to a vacuum cleaner comprising a housing, which accommodates an electrical suction unit, and a suction attachment, which can be coupled to the suction unit via a suction channel, which suction attachment is provided with a housing having two edges enclosing a corner, a primary suction opening extending in a bottom part of the suction attachment along each of the two edges, said primary suction openings being connected to a connecting channel which can be coupled to the suction channel, and the primary suction openings opening into a secondary suction opening near said corner.

[0003] A suction attachment and a vacuum cleaner of the types mentioned in the opening paragraphs are known from EP-A-0 930 041. The known suction attachment has a triangular housing. The two edges are two front edges of the suction attachment, which enclose an angle of approximately 90°. As a result, the housing has a pointed end which, viewed in a displacement direction of the suction attachment, points forwards. The primary suction openings, which extend along the front edges, are channel-shaped and connected to the connecting channel, which comprises a tubular coupling member by means of which the suction attachment can be coupled to a suction tube of the vacuum cleaner. The primary suction openings meet in the pointed end of the housing and, at this location, they open into the secondary suction opening which is formed in the pointed end of the housing. In operation, the primary suction openings are used to clean comparatively large floor areas, the suction attachment being moved over the floor area in the displacement direction. The secondary suction opening is used to clean narrow areas and corners. As the secondary suction opening is provided in the pointed end of the housing, and the angle enclosed by the front edges is approximately 90°, in particular corners can be readily reached by the secondary suction opening.

[0004] A drawback of the known suction attachment and the known vacuum cleaner resides in that the total suction power of the suction attachment is distributed over the primary suction openings and the secondary suction opening. As a result, the suction power near the secondary suction opening is comparatively small, so that the cleaning effect of the known suction attachment is limited in narrow areas and corners.

[0005] It is an object of the invention to provide a suction attachment and a vacuum cleaner of the types mentioned in the opening paragraphs, the total suction power of the suction attachment being comparable to the total suction power of the known suction attachment, but a larger suction power being attainable near the secondary suction opening.

[0006] To achieve this object, a suction attachment in accordance with the invention is characterized in that the suction attachment comprises at least two suction portions, said two edges, said two primary suction openings and said secondary suction opening being provided in a first one of the suction portions, and at least a second one of the suction portions comprising a suction opening which can be shut off from the connecting channel.

[0007] To achieve this object, a vacuum cleaner in accordance with the invention is characterized in that the suction attachment employed therein is a suction attachment in accordance with the invention.

[0008] As regards the suction attachment in accordance with the invention, the total dimensions of said suction portions and of the suction openings present therein are comparable to the dimensions of customary suction attachments, such as for example the above-mentioned suction attachment, and to the dimensions of the suction openings present therein. In the suction attachment in accordance with the invention, the total suction power is distributed over said suction portions. As the suction opening of at least the second suction portion can be shut off from the connecting channel, the overall suction power can be partly or wholly concentrated in the first suction portion. As the dimensions of the first suction portion, and of the primary and secondary suction openings present therein, are substantially smaller than the total dimensions of said suction portions, and of the suction openings present therein, a suction power is attained near the primary and secondary suction openings of the first suction portion which, if the total suction power is concentrated in the first suction portion, is larger than the suction power attained near these suction openings if the overall suction power is distributed over all suction portions. In this manner, an increased suction power is achieved also near the secondary suction opening, so that the application of the secondary suction opening in narrow areas and corners results in a higher cleaning effect.

[0009] A particular embodiment of a suction attachment in accordance with the invention is characterized in that the connecting channel forms part of a central portion of the suction attachment, and in that the two suction portions form a foot which can be rotated relatively to the central portion about an axis of rotation which extends substantially perpendicularly to an imaginary plane with which the suction attachment rests, in operation, on a surface to be cleaned, the suction opening of the second suction portion being capable of being shut off from the connecting channel by a rotary movement of the foot about said axis of rotation. As the suction opening of the second suction portion can be shut off from the connecting channel by a rotary movement of the foot about said axis of rotation, the suction power can be concentrated in the first section portion by means of a comparatively simple action of the user. Said foot has comparatively large dimensions, so that a mechanical torque necessary to rotate the foot is achieved by exerting a comparatively small force on the foot. As said axis of rotation extends substantially perpendicularly to said imaginary plane, it is achieved that an orientation of the central portion, by means of which central portion the suction attachment can be coupled to the vacuum cleaner, substantially does not change with respect to the surface to be cleaned when the foot is rotated about said axis of rotation. By virtue of these measures, the ease of use of the suction attachment is increased substantially.

[0010] A further embodiment of a suction attachment in accordance with the invention is characterized in that the two suction portions are identical, the suction openings of the first suction portion and the suction openings of the second suction portion being capable of being shut off from the connecting channel by a rotary movement of the foot about said axis of rotation from a first position to, respectively, a second position and a third position. In this further embodiment, both suction portions of the suction attachment have primary suction openings which open into a secondary suction opening near a corner enclosed by two edges. A rotary movement of the foot to the second position causes the suction openings of the first suction portion to be shut off from the connecting channel, as a result of which the suction power is concentrated in the primary and secondary suction openings of the second suction portion. A rotary movement of the foot to the third position causes the suction openings of the second suction portion to be shut off from the connecting channel, as a result of which the suction power is concentrated in the primary and secondary suction openings of the first suction portion. By virtue thereof, the suction attachment has a large number of applications.

[0011] A still further embodiment of a suction attachment in accordance with the invention is characterized in that, in the first position, the two suction portions, viewed in a width direction perpendicular to a displacement direction of the suction attachment, are situated on either side of the central portion, said corners having the secondary suction openings of the two suction portions, viewed in the width direction, forming end portions of the foot, while the foot is rotated, in the second position and in the third position, through an angle of, respectively, +90° and −90° with respect to the first position. As the two corners, viewed in the width direction, form end portions of the foot, and the foot is rotated, in the second position and in the third position, through an angle of, respectively, +90° and −90° with respect to the first position, in the second position, wherein the suction power is concentrated in the second suction portion, the corner having the secondary suction opening of the second suction portion points forward, viewed in the displacement direction, while, in the third position, wherein the suction power is concentrated in the first suction portion, the corner having the secondary suction opening of the first suction portion points forward, viewed in the displacement direction. By virtue thereof, using the suction power concentrated in one of the suction portions, a narrow area or corner to be cleaned can be reached by displacing the suction attachment in the customary displacement direction towards the narrow area or the corner. By virtue thereof, the ease of use of the suction attachment is further improved.

[0012] A particular embodiment of a suction attachment in accordance with the invention is characterized in that the central portion is provided with a substantially semi-cylindrical shut-off member, which is concentrically arranged with respect to the axis of rotation, and with a connecting duct into which the connecting channel opens, which connecting duct, viewed in a direction parallel to the displacement direction, is arranged next to the shut-off member and extends parallel to the width direction, which connecting duct, in the first position, connects together the primary suction openings of the two suction portions and the connecting channel, and, in the second position, the connecting duct connects together the primary suction openings of the second suction portion and the connecting channel, and the shut off member shuts off the primary suction openings of the first suction portion from the connecting channel, while, in the third position, the connecting duct connects together the primary suction openings of the first suction portion and the connecting channel, and the shut-off member shuts off the primary suction openings of the second suction portion from the connecting channel. By using said substantially semi-cylindrical shut-off member and said connecting duct, it is achieved in a manner which, from the constructional point of view, is both practical and simple that the two suction portions can be shut off from or connected to the connecting channel by a rotary movement of the foot about the axis of rotation.

[0013] A further embodiment of a suction attachment in accordance with the invention is characterized in that the two edges of each suction portion jointly enclose a comparatively small acute-angled corner, whereas the edges of the first suction portion and the edges of the second suction portion jointly enclose comparatively large obtuse-angled corners. As the two edges of each suction portion jointly enclose a comparatively small acute-angled corner, the suction attachment can particularly suitably be used to clean narrow areas by means of a suction power that is concentrated in one of the corners. As the edges of the first suction portion and the edges of the second suction portion jointly enclose comparatively large obtuse-angled corners, the adjoining edges of the first and the second suction portion can particularly suitably be used, in the first position of the foot, to clean along straight wall parts or baseboards.

[0014] These and other aspects of the invention will be apparent from and elucidated with reference to the embodiment(s) described hereinafter.

[0015] In the drawings:

[0016]FIG. 1 diagrammatically shows a vacuum cleaner in accordance with the invention,

[0017]FIG. 2 shows a suction attachment in accordance with the invention, which is used in the vacuum cleaner shown in FIG. 1,

[0018]FIG. 3a is a bottom view of the suction attachment, as shown in FIG. 2, in a first position of a rotatable foot of the suction attachment,

[0019]FIG. 3b is a bottom view of the suction attachment, as shown in FIG. 2, in a second position of the rotatable foot,

[0020]FIG. 4 is a diagrammatic, cross-sectional view taken on the line IV-IV in FIG. 3a, and

[0021]FIG. 5a through FIG. 5d diagrammatically show the suction attachment, as shown in FIG. 2, in four different positions of the rotatable foot.

[0022] The vacuum cleaner in accordance with the invention, as diagrammatically shown in FIG. 1, is a so-called cylinder vacuum cleaner, which comprises a housing 1 which can be displaced by means of a number of wheels 3 over a surface 5 to be cleaned. The housing 1 accommodates an electrical suction unit 7, which is only diagrammatically shown in FIG. 1. The vacuum cleaner further comprises a suction attachment 9 in accordance with the invention, which is provided with a housing 11. In an operating position shown in FIG. 1, the suction attachment rests, at the location of an imaginary bottom plane 13, on the surface 5 to be cleaned, which suction attachment 9 has to be moved by the user over the surface 5 to be cleaned in a displacement direction X. The suction attachment 9 is detachably coupled to the housing 1 of the vacuum cleaner via a suction channel 15, which comprises a metal suction tube 17 and a flexible suction hose 19. The suction attachment 9 comprises a tubular connecting channel 21 by means of which the suction attachment 9 is detachably coupled to the suction tube 17, while the suction tube 17 is detachably coupled to a tubular handle 23 attached to the suction hose 19, and the suction hose 19 is detachably coupled to an input 25 of the housing 1 of the vacuum cleaner. The input 25 opens into a dust chamber 27 of the housing 1, which is connected, via a filter 29, to the suction unit 7. In operation, the suction unit 7 generates, via the dust chamber 27 and the suction channel 15, an underpressure in the suction attachment 9, under the influence of which dust and dirt particles present on the surface 5 to be cleaned are drawn via suction openings, to be described hereinafter, in the suction attachment 9 and via the suction channel 15 to the dust chamber 27 where they are collected in a replaceable dust bag.

[0023] The suction attachment 9 in accordance with the invention is shown in detail in FIG. 2. The suction attachment 9 is provided with a central portion 31 which comprises the connection channel 21. The central portion 31 further comprises a substantially cylindrical part 33. The suction attachment 9 further comprises a first suction portion 35 and a substantially identical second suction portion 37. The two suction portions 35 and 37 jointly form a foot 39 which is journaled so as to be rotatable with respect to the cylindrical part 33 about an axis of rotation 41 extending substantially perpendicularly to the displacement direction X and substantially perpendicularly to the imaginary bottom plane 13. The first suction portion 35 has a front edge 43 and a rear edge 45 which enclose a comparatively small acute angle α, while the second suction portion 37 has a front edge 47 and a rear edge 49 which enclose a substantially identical angle α. The front edge 43 of the first section portion 35 and the front edge 47 of the second suction portion 37 enclose a comparatively large obtuse angle β, while the rear edge 45 of the first suction portion 35 and the rear edge 49 of the second suction portion 37 enclose an identical angle β. In the example shown, the angle α is approximately 30° and the angle β is approximately 150°. As a result, the foot 39 is substantially diamond-shaped and substantially symmetrical with respect to a first axis of symmetry 51, which extends through both angles α, and with respect to a second axis of symmetry 53, which extends through the two angles β. FIG. 2 shows the foot 39 in a first position with respect to the central portion 31, wherein the two suction portions 35 and 37 are situated, viewed in a width direction Y perpendicular to the displacement direction X and the axis of rotation 41, on either side of the central portion 31, and wherein the two angles α, viewed in the width direction Y direction, form the end portions of the foot 39.

[0024]FIG. 3a is a bottom view of the suction attachment 9, the foot 39 being in the above-mentioned first position relative to the central portion 31. As shown in FIG. 3a, the first suction portion 35 comprises a first channel-shaped primary suction opening 55, which extends along the front edge 43 in a bottom part 57 of the foot 39, and a second channel-shaped primary suction opening 59, which extends along the rear wall 45 in the bottom part 57. The primary suction openings 55 and 59 meet near the corner of the first suction portion 35, where the two primary suction openings 55 and 59 open into a secondary suction opening 61 of the first suction portion 35, which secondary suction opening extends as far as a side edge 63 of the first suction portion 35, connecting together the front edge 43 and the rear edge 45. Near the central portion 31, the two primary suction openings 55 and 59 are connected to each other by means of a transverse channel 65 provided in the bottom part 57. Similarly, the second suction portion 37 comprises a first channel-shaped primary suction opening 67, which extends along the front edge 47 in the bottom part 57, and a second channel-shaped primary suction opening 69, which extends along the rear edge 49 in the bottom part 57. The primary suction openings 67 and 69 meet near the corner of the second suction portion 37, where the two primary suction openings 67 and 69 open into a secondary suction opening 71 of the second suction portion 37, which secondary suction opening extends as far as a side edge 73 of the second suction portion 37, connecting together the front edge 47 and the rear edge 49. Near the central portion 31, the two primary suction openings 67 and 69 are interconnected by means of a transverse channel 75 provided in the bottom part 57. As shown in FIG. 3a and FIG. 4, a substantially semi-cylindrical shut-off member 77, which is concentrically arranged relative to the axis of rotation 41 and extends substantially as far as the imaginary bottom plane 13, a connecting duct 79 extending parallel to the width direction Y, which connecting duct has an opening 81 into which the connecting channel 21 opens, and a comparatively narrow dam 83, which also extends substantially as far as the imaginary bottom plane 13 are arranged, viewed in a direction parallel to the displacement direction X, next to each other on the cylindrical portion 33 of the central portion 31.

[0025] In the first position of the foot 39 with respect to the central portion 31, as shown in FIG. 3a, the connecting duct 79 connects both the primary suction openings 55, 59 of the first suction portion 35 and the primary suction openings 67, 69 of the second suction portion 37 to the connecting channel 21 via the opening 81, so that the total suction power of the suction unit 7 is distributed over the primary and secondary suction openings 55, 59, 61 of the first suction portion 35, and the primary and secondary suction openings 67, 69, 71 of the second suction portion 37. As, in the first position of the foot 39, the two suction portions 35, 37 are situated, viewed in the width direction Y, on either side of the central portion 31, and the total suction power is distributed over the two suction portions 35, 37, the suction attachment 9 is suitable, in this position, for cleaning comparatively large floor areas by displacing the suction attachment 9 in the displacement direction X. FIG. 3b shows a second position of the foot 39 with respect to the central portion 31, wherein the foot 39 is rotated by the user from the first position shown in FIG. 3a through an angle of 90° about the axis of rotation 41. As shown in FIG. 3b, in this second position only the primary suction openings 67, 69 and the secondary suction opening 71 of the second suction portion 37 are connected to the connecting channel 21 via the connecting duct 79 and the opening 81. In this second position, the primary suction openings 55, 59 and the secondary suction opening 61 of the first suction portion 35 are shut off from the connecting duct 79 and the connecting channel 21 by the semi-cylindrical shut-off member 77. The total suction power of the suction unit 7 is thus concentrated in the second suction portion 37 and distributed exclusively over the primary suction openings 67, 69 and the secondary suction opening 71 of this suction portion 37. In the second position of the foot 39, the corner of the second suction portion 37 points forward, viewed in the displacement direction X, so that, in this position, the suction attachment 9 can suitably be used to clean narrow areas or corners by means of displacements of the suction attachment 9 in the customary displacement direction X. As the total suction power is concentrated in the second suction portion 37, the suction power provided near the primary suction openings 67, 69 and near the secondary suction opening 71 is much larger than the suction power provided, in the first position of the foot 39 near these suction openings 67, 69, 71. As a result, the suction attachment 9 has a comparatively high cleaning effect, in particular, in corners and narrow areas which are only partly accessible to the suction attachment 9. The user can rotate the foot 39 about the axis of rotation 41 in a comparatively simple manner which, in view of the large dimensions of the foot 39, requires little effort. As the axis of rotation 41 extends perpendicularly to the imaginary bottom plane 13, the orientation of the central portion 31 and the connection channel 21 almost does not change with respect to the surface S to be cleaned when the foot 39 is rotated, so that also the position of the suction tube 17 remains substantially unchanged. By virtue of these properties, the suction attachment 9 is very easy to use. As the angle α enclosed by the front edge 47 and the rear edge 49 is comparatively small, the suction attachment 9 can particularly suitably be used, in the second position of the foot 39, to clean comparatively narrow areas. As the angle β enclosed by the two front edges 43 and 47 is comparatively large, the adjoining front edges 43 and 47 can particularly suitably be used, in the first position of the foot 39, to clean along straight wall portions or baseboards.

[0026] The above-described first position and second position of the foot 39 relative to the central portion 31 are diagrammatically shown in FIG. 5a and FIG. 5b. The foot 39 can also be rotated by the user from the first position shown in FIG. 5a through an angle of −90° about the axis of rotation 41 to a third position diagrammatically shown in FIG. 5c, and through an angle of 180° about the axis of rotation 41 to a fourth position diagrammatically shown in FIG. 5d. As can be derived from FIG. 3a and FIG. 3b, in the third position of the foot 39, only the primary suction openings 55, 59 and the secondary suction opening 61 of the first suction portion 35 are connected to the connecting channel 21 via the connecting duct 79 and the opening 81. The primary suction openings 67, 69 and the secondary suction opening 71 of the second suction portion 37 are shut off, in the third position, from the connecting duct 79 and the connecting channel 21 by the semi-cylindrical shut-off member 77. The total suction power of the suction unit 7 is thus concentrated, in the third position of the foot 39, in the first suction portion 37 and distributed only over the primary suction openings 55, 59 and the secondary suction opening 61 of the first suction portion 35. In the third position of the foot 39, the corner of the first suction portion 35, viewed in the displacement direction X, points forward, so that, in this position as well as in the first position, the suction attachment 9 can suitably be used for cleaning, by means of concentrated suction power, narrow areas or corners by displacing the suction attachment 9 in the customary displacement direction X. As can also be derived from FIG. 3a and FIG. 3b, in the fourth position of the foot 39, the connecting duct 79 connects both the primary suction openings 55, 59 of the first suction portion 35 and the primary suction openings 67, 69 of the second suction portion 37 to the connecting channel 21 via the opening 81, so that the total suction power of the suction unit 7 is distributed over the primary and secondary suction openings 55, 59, 61 of the first suction portion 35 and the primary and secondary suction openings 67, 69, 71 of the second suction portion 37. Thus, in the fourth position of the foot 39 as well as in the first position of the foot 39, the suction attachment 9 can suitably be used to clean comparatively large floor areas by displacing the suction attachment 9 in the customary displacement direction X. As the foot 39 can be rotated through an angle of +90° as well as through an angle of −90° from the first position to a position wherein the suction power is concentrated in the suction portion 35, 37 which, viewed in the customary displacement direction X, points forward, the application possibilities as well as the ease of use of the suction attachment 9 are further increased.

[0027] As shown in FIG. 3a, the suction attachment 9 further comprises, in the embodiment shown, four brushes 85, 87, 89 and 91 which are also provided in the bottom part 57 between, respectively, the front edge 43 and the primary suction opening 55, the rear edge 45 and the primary suction opening 59, the front edge 47 and the primary suction opening 67, and the rear edge 49 and the primary suction opening 69. The brushes 85, 87, 89 and 91 are provided on a lifting mechanism, not shown in detail in the Figures, which lifting mechanism co-operates with the cylindrical part 33 in such a manner that the brushes 85, 87, 89 and 91 are recessed in the bottom part 57, in the first and second position of the foot 39 shown in FIG. 5a and FIG. 5b, and project from the bottom part 57 in the third and fourth position of the foot shown in FIG. 5c and FIG. 5d. To show said co-operation, the brushes 85, 87, 89 and 91 are represented only in FIG. 5c and FIG. 5d by means of dashed lines. In the first and the second position of the foot 39, the suction attachment 9 can thus suitably be used to clean carpets, and, in the third and fourth position of the foot 39, it can suitably be used to clean smooth floors. It is to be noted that the suction attachment 9 is preferably provided with a locking mechanism having an unlocking button by means of which the foot 39 can be locked and unlocked, respectively, in each one of the four positions.

[0028] The vacuum cleaner in accordance with the invention, as described hereinabove, is a cylinder vacuum cleaner. It is to be noted that the invention also comprises other types of vacuum cleaners, such as, for example, so-called upright vacuum cleaners. In such an upright vacuum cleaner, the suction attachment is, for example, pivotably coupled to the housing of the vacuum cleaner, the housing of the vacuum cleaner being in a substantially upright position in the operating position.

[0029] It is further noted that the invention also comprises suction attachments including more than two suction portions. The invention includes suction attachments comprising suction portions which each have a corner having a secondary suction opening, and suction attachments comprising suction portions of which only one, or not every suction portion, has a corner having a secondary suction opening. In all these embodiments, the suction power can be entirely or partly concentrated in at least one suction portion, which is provided with a corner having a secondary suction opening, by closing the suction opening or suction openings of the other suction portion or of at least one of the other suction portions.

[0030] It is further to be noted that the invention also includes suction attachments wherein the primary suction openings present along the two edges of the first suction portion are combined so as to form a single primary suction opening, or wherein more than two primary suction openings are provided in the first suction portion.

[0031] Finally, it is noted that the invention also includes suction attachments which are embodied such that at least one of the suction portions can be shut off in a manner other than by rotation of the suction portions about a central portion of the suction attachment. For example, the invention also includes embodiments wherein the suction portions are arranged in a fixed position with respect to the connecting channel, and wherein at least one of the suction portions can be shut off from the connecting channel by means of a valve or another shutt-off mechanism which can be operated by the user by means of, for example, a button. 

1. A suction attachment for a vacuum cleaner, which suction attachment comprises a housing having two edges enclosing a corner, a primary suction opening extending in a bottom part of the suction attachment along each of the two edges, said primary suction openings being connected to a connecting channel which can be coupled to a suction unit of the vacuum cleaner, and said primary suction openings opening into a secondary suction opening near said corner, characterized in that the suction attachment comprises at least two suction portions, said two edges, said two primary suction openings and said secondary suction opening being provided in a first one of the suction portions, and at least a second one of the suction portions comprising a suction opening which can be shut off from the connecting channel.
 2. A suction attachment as claimed in claim 1, characterized in that the connecting channel forms part of a central portion of the suction attachment, and in that the two suction portions form a foot which can be rotated relatively to the central portion about an axis of rotation which extends substantially perpendicularly to an imaginary plane with which the suction attachment rests, in operation, on a surface to be cleaned, the suction opening of the second suction portion being capable of being shut off from the connecting channel by a rotary movement of the foot about said axis of rotation.
 3. A suction attachment as claimed in claim 2, characterized in that the two suction portions are identical, the suction openings of the first suction portion and the suction openings of the second suction portion being capable of being shut off from the connecting channel by a rotary movement of the foot about said axis of rotation from a first position to, respectively, a second position and a third position.
 4. A suction attachment as claimed in claim 3, characterized in that, in the first position, the two suction portions, viewed in a width direction perpendicular to a displacement direction of the suction attachment, are situated on either side of the central portion, said corners having the secondary suction openings of the two suction portions, viewed in the width direction, forming end portions of the foot, while the foot is rotated, in the second position and in the third position, through an angle of, respectively, +90° and −90° with respect to the first position.
 5. A suction attachment as claimed in claim 4, characterized in that the central portion is provided with a substantially semi-cylindrical shut-off member, which is concentrically arranged with respect to the axis of rotation, and with a connecting duct into which the connecting channel opens, which connecting duct, viewed in a direction parallel to the displacement direction, is arranged next to the shut-off member and extends parallel to the width direction, which connecting duct, in the first position, connects together the primary suction openings of the two suction portions and the connecting channel, and, in the second position, the connecting duct connects together the primary suction openings of the second suction portion and the connecting channel, and the shut off member shuts off the primary suction openings of the first suction portion from the connecting channel, while, in the third position, the connecting duct connects together the primary suction openings of the first suction portion and the connecting channel, and the shut-off member shuts off the primary suction openings of the second suction portion from the connecting channel.
 6. A suction attachment as claimed in claim 4, characterized in that the two edges of each suction portion jointly enclose a comparatively small acute-angled corner, whereas the edges of the first suction portion and the edges of the second suction portion jointly enclose comparatively large obtuse-angled corners.
 7. A vacuum cleaner comprising a housing, which housing accommodates an electrical suction unit, and a suction attachment, which can be coupled to the suction unit via a suction channel, which suction attachment is provided with a housing having two edges enclosing a corner, a primary suction opening extending in a bottom part of the suction attachment along each of the two edges, said primary suction openings being connected to a connecting channel which can be coupled to the suction channel, and the primary suction openings opening into a secondary suction opening near said corner, characterized in that the suction attachment is a suction attachment as claimed in claim 1, 2, 3, 4, 5 or
 6. 